A method was developed to deposit phosphorus-doped ZnO films using atomic layer deposition where the oxygen, zinc and phosphorus atoms were supplied by ozone, diethylzinc and trimethylphosphite, respectively. X-ray photoelectron spectroscopy established that the phosphorus was present in the +5 oxidation state, where it substituted for larger zinc ions to cause a measurable decrease in the c lattice constant of the textured polycrystalline films. The electrical behavior of the as-deposited film was n-type, but this changed to p-type following rapid thermal annealing in oxygen. The temperature of the n-to p-type transition decreased as the phosphorus concentration increased. (C) 2011 The Electrochemical Society. [DOI: 10.1149/1.3537326] All rights reserved.